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Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

A red color glass bulb in a fire sprinkler head indio cates a temperature rating of: (A) 135°· 170° (8) 175°· 225° (C) 250°· 300° (0) 325°· 375°

(A) 135°- 170° Red or Orange. Temperature classification = Ordinary When the temperature in a space reaches a given point the liquid contained in the bulb will expand and cause the bulb to break, allowing water to pass through it. The bulb is available in various colors which indicate a wide range of temperature sensitivity, from 135° to 650°F. (B) 175°· 225° Yellow or Green = Intermediate (C) 250°· 300° Blue = High (D) 325°· 375 0 Purple = Extra High 400° - 650° Black = Very Extra to Ultra High

What is the main reason to use task lighting? (A) To add direct light to task areas. (8) To conserve energy. (C) To increase flexibility. (D) To reduce electrical costs.

(B) To conserve energy. Task lighting avoids the unnecessary lighting of an entire space and reduces energy demands. As an alternative to ceiling mounted lighting, task lighting can be combined with furniture mounted or freestanding Indirect fIxtures to improve ambient lighting. Characteristics of this combination include: Flexibility of furniture layout. Lower initial construction cost. Lower energy requirements. Ease of access for maintenance. Possible increase in heat and noise (from ballast). Veiling reflections. Difficulty In lighting large or irregular shaped spaces. Not easily automated for switching and dimming. Redundancy may be required to accommodate both left and right handed users. Ideally, the system should be flexible, so the user can adjust and reposition the light as necessary.

Grey water is NOT derived from which of the following? (A) Lavatories (8) Roof drains (C) Effluent (D) Swales

(C) Effluent Grey water is recycled water from water systems and site drainage that does not contain human waste. It is used as a water conservation measure for watering plants and flushing toilets. Grey water is non-potable.

No. 0000 or 4/0 is what type of electrical wire? (A) Telephone (B) Major appliance (C) Main feed (D) None of the above

(C) Main feed Under the American Wire Gauge (AWG) system, 0000 or 4/0 (pronounced "four aught") is the largest wire at nearly 112 inch in diameter.

The objective of a fire protection system is to make a building which of the following? (A) Fireproof (8) Fire retardant (C) Fire resistant (D) Non·combustible

(Cl Fire resistant The objective of a fire·protection system is to enable a structure to resist fire long enough for the safe evacuation of all occupants. Through the use of fire resistant materials, fire suppression, automatic detectors, and implementation of model codes, fires today are typically confined to small areas rather than resulting in the loss of an entire floor, building, or adjacent buildings. In order of importance, the three objectives of fire safety are: 1. Protection of life 2. Protection of property 3. Maintaining building operation

Effluent flows best in a drainage pipe pitched at what angle? (A) 45 degrees (B) 1/8 inch per foot (e) 1/2 inch per foot (D) 1/4 inch per foot

(D) 1/4 inch per foot This slope is best for the flow of effluent in a drainage pipe. 1/8 inch per foot would not provide enough water velocity and 1/2 inch per foot causes liquids to flow too quickly. A 45-degree slope is required for sewage that flows entirely by gravity. For supply water under pressure, 90 degrees is allowable.

Which of the following would be appropriately designed as a dead space? (A) An auditorium (B) A church (C) An office (D) A hospital patient room

(D) A hospital patient room A dead space is appropriate for a hospital because it would be quiet. The room would contain a large amount of porous materials to absorb sound waves. Auditoriums and churches are designed as live spaces. These are spaces in which sound waves reverberate due to reflective surfaces. The greater the ratio of reflected sound to directly received sound, the more a space is considered live. Offices need a mixture of live and dead spaces, allowing for some white noise.

A particular wall has a high Sound Transmission Class (STC) rating yet has a relatively high degree of sound transmission. What may be the cause? (A) Poor construction (8) A keyhole (C) A window (0) All of the above

(D) All of the above A wall assembly with a door, window, grill or other similar opening is called a composite wall. Any break in the integrity of the partition is a potential sound leak. The overall performance of the assembly is largely diminished by even the smallest leak such as gaps, hairline cracks or a keyhole in a door. Therefore, care must be taken not only in the location, but the installation of openings, especially doors and windows. Misalignment of doors or gaps around window frames must be completely sealed in order to maintain sound isolation. Other common leaks include medicine cabinets, electrical outlets, or openings for pipes and ducts. Diffraction is the process by which sound waves bend and pass through very small openings.

Which of the following lamps is the least energy efficient? (A) Fluorescent (8) Mercury (C) Sodium (D) Incandescent

(D) Incandescent DISADVANTAGES: short life, high life-cycle replacement cost, larger heat gain, voltage sensitivity. ADVANTAGES: low initial cost, instant start and restart, dimmable, good color rendition for skin tones, focusability. Where access is difficult. They can be operated slightly, undervoltage to extend life. Overvoltage operation is possible when maximum light output is required for a relatively short time, however, this shortens lamp life.

one psi can lift water how high?

1 lb/square inch can lift water 2.3 feet high

Name these common abbreviations: 1. C/B 2. A 3. CCT 4. EM 5. F 6. GND 7. HP 8. GFCI 9. LTG 10. N 11. NO 12. OC 13. AFF 14. NC 15.NIC 16. T 17. UON 18. SD 19. UG 20. WP 21. V 22. HID

1. Circuit Breaker 2. Amperes 3. Circuit 4. Emergency 5. Fuse 6. Ground 7. Horsepower 8. Ground Fault Circuit Interrupter 9. Lighting 10. Neutral 11. Normally Open Wiring Contact 12. On Center 13. Above Finish Floor 14. Normally Closed Wiring Contact 15. Not In Contract 16. Thermostat 17. Unless Otherwise Noted 18. Smoke Detector 19. Underground 20. Weatherproof 21. Volts 22. High Intensity Discharge Lamp

Name the appropriate term for each of the following definitions: 1. The transfer of thermal energy through a fluid medium (liquid or gas) where the cool molecules of water or air, for example, absorb heat from a warm surface. The molecule rise, are carried away, then cool and fall. 2. The transfer of heat by electromagnetic waves from one surface to a cooler detached surface across an open space. The rate of transfer depends upon the temperature differential, the thermal absorptivity of the surfaces, the orientation of the surface, and the distance separating the energy source and the receiving surface. 3. Heat transfer through a solid material, from hotter molecules to cooler molecules through direct contact. Rate of transfer depends primarily on surface temperature.

1. Convection 2. Radiation 3. Conduction less important for building materials than for human comfort, evaporation is a means of transferring heat to a cooler environment. The rate of heat transfer is dependent primarily on humidity, air movement, and air temperature. If an object is a different temperature than the environment, heat will flow from the hotter to the colder.

Name two methods for controlling HVAC noise in a building.

1. Create a separate foundation for the equipment 2. Use vibration Isolators (either springs or neoprene pads) between the equipment and the building foundation. The use of fleecy internal duct liners for both thermal and sound insulation should be avoided. An inherent problem is the absorption of contaminants by the insulation. This can lead to a reduction in the Indoor Air Quality (IAQ).

Name the appropriate term for each of the following definitions. 1. A water-supply system that uses a pressurized tank, usually in the basement, to supply water under pressure to the floors above. 2. A water·supply system used In tall buildings in which water from the street main is pumped to a rooftop storage tank and distributed to the building under pressure from gravity. Pressure is determined largeIy by the height difference between the tank and the floor served. Significant weight on the roof may require additional structure. 3. A water-supply system that uses the existing pressure In the water main to supply the fixtures, for small, low rlse buildings with a moderate demand. A pump can be incorporated to Increase distribution.

1. Hydropneumatic 2. Downfeed distribution 3. Upfeed distribution

Name two automatic fire detection systems classified as early·warning types.

1. IONIZATION DETECTOR: This device senses the microscopic particles of combustion during the Incipient stage of a fire. Since the reaction time depends on how quickly the particles reach the detector, they are best used indoors in spaces with minimal air currents. Because hot air prevents the particles from reaching the detector, they should not be installed on relatively warm ceilings or where heat can accumulate. They also should not be installed in areas such as kitchens where the particles of combustion are to be expected. Also, in the incipient stage of a fire, combustion gases can be detected by a gas sensing fire detector. 2. PHOTOELECTRIC DETECTOR: Once a fire has passed the incipient stage this type of detector is more effective. Combustion particles visible as smoke will obscure a beam of light in the device and trigger the alarm. This type of detector is effective in the second stage of a fire, the smoldering stage.

Name the two main functions of an automatic thermal control system.

1. It automatically adjusts heating or cooling output. 2. It distributes the air between various zones as required.

Name six types of security systems and describe their characteristics.

1. PASSIVE INFRARED (PIR) DETECTOR: Senses any rapid change in Infrared radiation, or heat within the zone that the detector is focused. Used when motion within the zone is expected. Can be triggered by HVAC systems. 2. MOTION DETECTOR: Using either microwave or ultrasonic frequencies, these systems detect motion by the Doppler effect. Since lateral movement may be undetected. the device should be placed in line with the intruders likely path of travel. 3. MECHANICAL MOTION DETECTOR: Contains a spring mounted contact suspended within another contact surface. Any motion from the surface on which the device sits will cause the contacts to trigger the alarm. They usually have a sensitivity adjustment to prevent false alarms. 4. PHOTOELECTRIC DEVICE: They are triggered by an interruption In a laser or infrared beam. When used outside, they are susceptible to false alarms from dust, birds, weather etc. 5. ACOUSTIC DETECTOR: Triggered when the noise level exceeds the preset limit. They can also be set to respond to a certain frequency such as the sound of breaking glass. 6. NORMALLY CLOSED CONTACT DEVICE: These systems commonly employ magnetic strips or spring loaded devices at doors and windows. They are triggered when the circuit A combination of technologies is often used to reduce false alarms.

Name four ways in which heat can enter a space.

1. Solar radiation through windows. 2. Heat conduction through the building envelope. 3. Heat generated by people and equipment. 4. Warm outdoor air entering through vents or by infiltration.

Name three systems for heating water?

1. WATER HEATER: An insulated storage tank that supplies a fixed quantity of heated water with a predictable recovery time. 2. CONTINUOUS LOOP: A two pipe, closed loop system requiring a circulator pump to maintain temperature at the fixture. 3. INSTANTANEOUS: A tankless hot water system that heats the water directly at the point of use.

Name the appropriate term for each of the following definitions: 1. A constructed shelf below a window, designed to reflect light up towards a ceiling and distribute it back into a space. 2. A unit of Illumination based on the metric system. It is equal to 1 meter·candle or 1 lumen/m" In the U.S. where the foot Is the unit of length, 1 footcandle equals 1 lumen/ft" 3. A complete lighting unit consisting of a light source, reflector, refractor and all the parts necessary for the fixture, housing, and power-supply connections.

1. light Shelf 2. lux 3. luminaire

A six story building with a floor-to-floor height of 14'-0" has a plumbing requirement of at least 20 psi at a fixture on the top floor. How much pressure is required at the street main to meet the minimum requirement at the fixture?

56.5 psi lift = 6 stories x 14'-0" lift = 84'-0" Since 1 psi of pressure can lift a column of water to a height of 2.3 feet, then; 84 + 2.3 = 36.5 psi 36.5 psi will raise the water to 84 feet. The fixture requires 20 psi to function. Therefore, 36.5 psi + 20 psi = 56.5 psi is required.

When there is no heat loss from the human body due to conduction, convection, or radiation, what is the outside air temperature?

98.6 degrees Fahrenheit, or when air temperature is equal to body temperature. When the air temperature rises above body temperature, the heat flow reverses and evaporation takes place.

Name the area highlighted on the psychrometric chart.

A conceptual comfort zone. This zone represents an area where different combinations of dry bulb temperatures (air temps.) and relative humidity are considered comfortable by most North Americans, seated, in short sleeves, in shade, with no wind. Subjective tests are used to determine these effective temperature ranges. The comfort zone can be expanded by altering environmental variables. For example, moving to the left on the chart (lower air temps.) will continue to be comfortable if there is additional sun exposure, clothing, or physical activity. likewise, moving to the right on the chart (higher air temps.), comfort can be maintained by adding air movement (wind), removing clothing, or reducing physical activity.

Which climate has large diurnal temperature swings?

A hot arid climate has large diurnal (day to night) temperature swings. Houses that are open to an inner courtyard with water elements and/or planting stay cooler in such climates, because evaporating moisture cools the air entering the house. Small, high windows on exterior walls allow hot air to escape while keeping in cool air.

Soil Stack

A large pipe that connects all the soil and waste lines throughout a building to a vent at the roof.

Effective Temperature

A measure of a combination of several comfort indexes; dry-bulb temperature, relative humidity, radiant energy and convection. An index of thermal sensation, not a measure of actual thermometer temperature.

What is wet bulb temperature and how is it measured?

A measure of relative humidity. It is determined by using a sling psychrometer which is made up of two thermometers, side by side, one covered with a wet sock. This instrument is swung in the air so that moisture from the wet sock will evaporate. The drier the air, the more evaporation takes place and the lower the relative humidity.

Decibel

A measure of sound intensity level. (x) IL=10 log I/Io Where: IL is equal to the intensity level in decibels. I is equal to the intensity of sound heard (Watts/cm sq.). Io is equal to the minimum reference intensity, the lowest sound that can be heard with the human ear. Named after Alexander Graham Bell.

A new restaurant requires that a sewer system be installed before construction. What type of sewer connections will be required?

A new building requires a sanitary sewer connection as well as a separate storm sewer.

Describe the characteristics of correct vapor barrier placement.

A tight well-insulated exterior wall is critical for energy conservation and moisture control. Vapor barriers should be placed at the location where cool surfaces meet warm moist air. On the outside in hot, humid climates, and on the inside in cold climates. The vapor barrier will prevent condensation, which can promote microbial growth such as mold and bacteria and lead to Indoor Air Quality (IAQ) problems.

Sabin

A unit of sound absorption. Named after the American physicist Wallace C. W. Sabine. One unit is equal to one square foot of a totally absorptive surface.

Vent Stack

A vertical vent pipe that provides air circulation to and from all plumbing fixtures and extends above the roof line to the open air.

Hydronic Systems

A water mechanical system used only for heating. Many of these systems are also radiant systems. Some systems circulate hot water or steam through registers, pipes in the floor, etc., and radiate heat into the space. These systems are sometimes combined with forced air systems.

Outdoor Design Temperature

A working average of low temperatures within a particular region. It is used as a factor in determining heat loss of a building.

Identify these pipe hanger types.

A. Clevis Hanger B. Strap Hanger C. Trapeze Hanger Pipe hangers often incorporate springs or rollers into their design and are used to remedy problems such as vibration, noise, and expansion. Hangers are required at turns and junctions and spacing is determined by pipe size.

Identify these electrical wiring and equipment symbols:

A. Concealed wiring and conduit. Slash lines indicate the number of conductors, excluding grounds. B. Exposed wiring and conduit. C. Surface mounted panelboard. D. Conductors crossing and connected. E. Ground connection F. Normally open contact G. Normally closed contact H. Fuse (20 amp) I. Circuit breaker l. Motor (15 horsepower) K. Motor starter L. Power wiring M. Control wiring

...

A. Vent Stack B. Stack Vent C. Soil Stack D. Cleanout E. Cleanout

Which of the following represents an extremely acidic pH reading? A. pH=5 B. pH=7 C. pH=9 D. pH=17

A. pH = 5 Acidity is measured by pH content of the water. Neutral water has a pH of 7. The greater the acidity, the lower the number. A pH above 7 represents basic or alkaline water. (Acidic water causes corrosion)

Tankless Water Heater

Also called an instantaneous water heater in which the water temperature is very quickly raised using a heating coil and sent directly to the fixture. They can accommodate central hot water systems or they can be installed adjacent to plumbing fixtures that only need occasional hot water. They can be powered by electricity or gas although gas fired units must be vented. They require a minimum of space, but due to the heating coil they may increase the friction in the supply system.

What is the difference between an electrical emergency system and a standby system?

An electrical emergency system is required by law to provide emergency power and lighting for human safety and the protection of property. A standby system supplies back-up power in case of disrupted service and is solely for the protection of property and equipment.

Sling Psychrometer

An instrument that measures relative humidity or wet bulb temperature and is composed of two thermometers, one with a wet sock on the bulb and one without. The instrument is swung in the air to cause evaporation. The temperature differential between the two thermometers is then compared to determine the relative humidity.

Inverse Square Law

Applies to sound and light intensity, which is inversely proportional to the square of the distance between the source and receiver.

What is the best height for a toilet seat in a handicap accessible stall?

Between 17 inches and 19 inches is acceptable.

BTU

British Thermal Unit. The amount of heat energy required to raise the temperature of one pound of water by one degree Fahrenheit.

How does Conductance differ from Resistance?

Conductance is the number of BTU's per hour that pass through one square foot of a material. Resistance is the reciprocal of conductance. In simple terms, Conductance is the amount of heat lost through one square foot of any given material per hour. Resistance, or R-value, of any material is the number of hours it would take for one BTU to pass through a material of a given thickness. The higher the R-value, or conversely, the lower the conductance, the better a material prevents heat loss.

Conduction

Conduction is the transfer of heat from one molecule to another through a substance. Not all substances conduct heat at the same speed. Metals and stone are considered good conductors since they can speedily transfer heat, but wood, paper, air, and cloth are poor heat conductors.

Air movement affects body heat by what processes?

Convection and Evaporation. The faster the air movement, the greater the rate of heat flow from convection and evaporation.

Solar heat gain through fenestration, outside air heat gain, internal heat gain from people and equipment, and transmission heat gain through the building envelope are all factors in the calculation of what?

Cooling load. These factors are the sources used to estimate, through calculations, the rate at which heat needs to be removed from a space in order to maintain human comfort.

What considerations determine the size of a water heater?

Daily peak hot-water demands and recharge time.

Fire sprinklers and finishes

Escutcheons and cover plates are cosmetic. They are available in many different finishes or may be painted. The head itself however, may not be painted due to the potential loss of fire detection sensitivity.

Glare

Extreme contrast between brightness and darkness that interferes with vision. 1. DIRECT GLARE: Brightness in the field of vision. 2. REFLECTED GLARE: Brightness reflected from other surfaces.

Latent Heat

Heat energy that causes a change of state, such as ice to water. Condensation in the air causes a heat-energy reduction. Transfer of heat energy is not to be confused with temperature, which is a measure of heat.

HDD and CDD

Heating Degree Days. HDD = sum of (65d - avg daily temp) for each day of heating season CDD= sum of (avg daily temp-65d)

What is the minimum clear space for a handicap accessible toilet stall?

Ideally, a handicap accessible toilet stall should have a 5-foot diameter clear space up to a height of 10 inches from the floor.

a. AZIMUTH (AZ) It is the angle of the sun measured clockwise from the North Point in the Northern Hemisphere and from the South Point in the Southern Hemisphere. b. ALTITUDE (ALT) It is the angle of the height of the sun measured perpendicular to the horizon.

Identify angles 'a' and 'b'.

Buildings can be designed to minimize the size of HVAC and lighting systems, thereby reducing energy consump· tion. Likewise, buildings can be desIgned to minimize the size of fire fighting systems. What role do fire sprinklers play in this system and how do they impact building design?

In conjunction with fire resistant building materials, fire and smoke compartmentation, lightning protection, fire detection and alarm systems, fire sprinklers are a proven automatic fire suppression system. Whereas fire fighting using hoses or standpipes may take several minutes to deploy. fire suppression from sprinklers begins within seconds of fire detection even in an unoccupied building. The sprinklers are in the immediate vicinity of the fire below and provide valuable time in the early stages of a fire. For these reasons, model codes may permit design flexibility in the form of an increase in allowable floor area or a greater spacing between exit stairs. Sprinklers may be incorporated into HVAC systems for energy conservation and their initial cost may be recovered quickly through lower insurance premiums. However, sprinkler systems must have adequate water supply and may require back-up power for pumping. The equipment is often unsightly and can be difficult to incorporate into the design. While sprinklers are very effective at fire suppression, water damage to building materials and building contents can be extensive.

what is the difference between a downfeed and a pneumatic system?

In the downfeed system, a tank mounted on the roof supplies water to the upper stories. The tank is filled to a certain level by water from the main that is boosted by a pump in the basement. (Note: Water can be pushed up from below to just about any height. However, it can never be sucked up from above to any height greater than 33 feet, which is the static head equivalent of atmospheric pressure of 14.7 psi.) The disadvantage of the downfeed system is the considerable weight added to the roof, which results in a heavier and more expensive structure, particularly in earthquake-prone areas. To avoid that, the pneumatic tank system uses a pressurized tank in the basement to supply higher levels. Some air is left in the tank, which can be compressed to act as a spring pushing up on the water in the tank.

What is the principal purpose of an electrical service disconnect?

It enables all electrical circuits in an entire building to be disconnected from a single switch.

What is the most important thing to consider when dealing with sanitary systems?

It is most important to keep the waste water from contaminating the water system. Sanitary waste can be categorized as grey water or black water. Black water contains human waste. Grey water can be recycled with very little treatment and is used for irrigation.

The eye is composed of a focusing device, a brightness control, and a color sensing surface. Name these parts of the eye.

LENS: Focuses. IRIS: Controls brightness. RETINA: Senses color, and black and white.

Effluent

Liquefied sewage that flows from a building's disposal system into the public sewer system or to a private, on-site system (septic tank or leach field).

Crack Method

Measures infiltration. Based on the total number of linear feet of cracks or joints around building elements such as doors and windows. The amount of infiltration, or leakage, per linear foot is determined by a table that accounts for wind speed and the type of opening. Another simpler yet less accurate method of measuring infiltration is known as the air·change method. In this method, the performance of existing buildings, regarding construction type and climate, is correlated to the characteristics of a proposed building. Very little information about the proposed building is necessary, however, this method tends to overestimate.

Microbial growth is the leading Indoor Air Quality (IAQ) contaminant. What is the main cause of this phenomenon and how can the architect minimize this occurrence?

Mold, bacteria. viruses, algae etc., are often caused by excessive indoor relative humidity. This is a problem particularly for hot-humid climates and may also be a problem in colder climates where condensation can occur on surfaces within the building envelope. The use of fiberglass or mineral wool for internal·ductwork insulation is to be avoided. If exposed to moisture it can harbor microbial growth, which, along with the fibers themselves, can get loose in the air stream and spread contamination. Carpet, acoustic tiles, textiles, vinyl wall covering and paint are also prone to contamination. To minimize the occurrence, the architect should: Eliminate the use of internal duct liners, specify products with anti-microbial additives. or use anti-microbial agents as a treatment Use correct placement of vapor barriers on the building envelope. On the outside in hot-humid climates; on the inside in cool climates. Provide easy access to all HVAC systems for maintenance.

Name some architectural concerns that may arise from using a refrigeration system.

Noise, vibration and heat. If possible the system should· be located outside of the building to prevent the transmission of vibration to the structure. Otherwise, a vibration isolator made with springs or neoprene pads should be placed under the equipment.

Vent Lines

Pipes extending up from a fixture and through the roof to allow airflow within a plumbing system. Keeps water pressure in the drainage system equalized.

What building components are affected, in length, by expansion and contraction but are not affected in diameter?

Pipes. They undergo significant changes in length due to thermal expansion. Pipes for long runs must be held in place with flexible supports and hangars.

PSI

Pounds per square inch. A measure of water and air pressure.

Resistance (R)

R=1/C Resistance (R) is the reciprocal of conductance (C) and is a measure of the insulating quality of a material. Conductivity measures a material's ability to conduct heat. Resistance increases as the thickness of a material increases.

SHGC

Solar Heat Gain Coefficient The amount of solar radiation that can pass through a window or skylight can be measured in terms of its solar heat-gain coefficient, or SHGC. SHGC is best described as a ratio where 1 equals the maximum amount of solar heat allowed through a window, and 0 equals the least amount possible allowed through. An SHGC rating of 0.30 means that 30% of the available solar heat can pass through the window.

Which type of mechanical system has a high initial cost but a low life cycle cost?

The Fan Coil System: Initially expensive because it requires a significant amount of piping (a 3 or 4 pipe system), but it is very efficient and can either heat, cool, or ventilate.

Specific Heat (Cp)

The ability of a material to store heat in relationship to the material's weight. Different materials are capable of storing different amounts of heat, even when they are at the same temperature. Specific heat is multiplied by a material's weight to determine thermal capacity.

Emissivity

The ability to, and rate at which a material absorbs and then emits radiant energy. It is measured from 0 to 1.0.

Mean Radiant Temperature (MRT)

The average temperature of all radiating surfaces within the line of sight of a body. Used to determine the comfort zone. If the MRT is high, then the comfort zone moves to a lower ambient temperature and vice versa. MRT is measured using a globe thermometer and is independent of air temperature.

Stack Vent

The length of pipe that rises above the highest fixture in a building. Used to vent the soil stack.

Relative Humidity

The percentage of water vapor in the air relative to the maximum amount of water the air can hold at a given temperature. With regard to human comfort, in a cold environment humidity is of little importance. In cold conditions heat is lost primarily by conduction, convection and radiation. However, in hot conditions, where heat is lost primarily by evaporation, humidity is critical. Whereas in cold conditions skin temperature is an important factor, in hot conditions the percentage of skin covered by water is more important. Levels of humidity can also be expressed as the dew point, wet-bulb temperature, and vapor pressure.

What is a heating or cooling load?

The rate at which heating or cooling needs to be removed or added into a space to maintain a comfortable room temperature.

Flux

The rate of flow of lumens or watts through a theoretical surface.

Due to the sun's path across the sky, which facade receives the most sunlight in winter? In summer?

The south facade receives the most sun in winter (in the Northern Hemisphere) when the angle of the sun is low. The east facade, the roof (including skylights), and the west facade receive the most amount of sun in the summer, when the angle of the sun is high. Overhangs play an important role, allowing the winter sun in and keeping out the summer sun.

Enthalpy

The sum of sensible heat and latent heat in a material.

Dew Point

The temperature at which water vapor in the air becomes saturated and condenses into water droplets. Dependent upon the dry bulb temperature. As the temperature drops, the air can no longer hold as much water vapor and the vapor condenses.

Degree Days

The temperature difference between an average 24 hour exterior temperature and an interior temperature of 65 degrees gives the number of degree days for one day. For example, an average outside temperature of 20 degrees Fahrenheit is recorded over a 24-hour period. The number of degree days, then, is 65 degrees - 20 degrees = 45 degrees. All degree-day values are added for an entire year to determine the annual degree-day total. Used to determine fuel needs and to size mechanical equipment.

delta-T

The temperature differential between inside and outside. usually during winter. determined by subtracting the outdoor temperature from the desired indoor temperature.

Type K, L, or M

These are the wall thickness classifications for copper tube used for water supply systems. Type K is the thickest, and type M is the thinnest. Copper tubing used for drainage, waste or vent installations is classified by the designation DWV. Each type of tubing has a continuous color marking along its length. K = Green L = Blue M = Red DWV = Yellow

Characteristics of plastic plumbing pipes.

These pipes are made of synthetic resins derived from materials like coal and petroleum. PVC (Polyvinyl Chloride) Is the most widely used material and is Suitable for supply of potable water if marked with the NatIonal SanItation 'foundation (NSF) seal. ABS (Acrylonitrile Butadiene Styrene) Is typically used for sanitary drainage, waste and vent (DWV) Installations. ADVANTAGES INCLUDE: Resistance to mineral deposits and corrosion Light weight Lower material cost than copper Flexibility and shock resistance make It suitable for applications such as mobile homes. DISADVANTAGES INCLUDE: To connect pipes and fittings a "solvent weld", permanent connection is used and therefore cannot be disassembled like copper piping. It Is not as easily recycled as copper. Unless treated with special pigments it will deteriorate when exposed to UV light. Due to Its flexibility, supports must be closer together than those used for metal pipe. Plastic softens under heat It should generally not be Subjected to water hotter than 180°F (82°C)

Dry Bulb Temperature (DB)

This is the ambient air temperature as measured by a common thermometer. It can be used together with globe temperature (the temperature measured by a globe thermometer which represents the balance between heat gained by radiation and heat lost by convection) and air velocity to calculate mean radiant temperature (MRT). The DB temperature itself is not an adequate indicator of comfort. However, in conjunction with other environmental factors, it greatly affects human perceptions of comfort, heat, and air quality.

(k)

This is the symbol for thermal conductivity. It is the ability of a material to transmit or conduct heat or electricity. This is based on the physical properties of the particular material, and is the amount of heat transmitted in one-hour through one square foot of a one-inch thick material for each degree Fahrenheit of temperature difference between the two surfaces of the material. Expressed in British Thermal Units (BTU).

Why is a vapor barrier placed on the warm side of insulation?

This location inhibits condensation from reaching the dew point by restricting the transmission of water vapor through a wall or roof cavity. It is placed on the outside of a construction assembly in a hot-humid climate and on the inside in a cold climate as in the drawing below.

Sensible Heat

Transferred heat energy that causes a change in the dry bulb temperature of a material but not a change of state.

Valves

Used to control the flow of water, They enable parts of a water system to be shut down for repairs without affecting the building's entire system.

What is the minimum diameter allowable for a plumbing stack?

Vents or stacks are sized based on the total accumulated, connected load at each story. As this load decreases, the size may be reduced. However, the stack diameter may not be reduced to less than one half the diameter of the largest stack size required.

Drainage Lines

Vertical and horizontal branches of pipe that carry waste water from the fixtures to a point of disposal. Drain pipes for water closets and urinals are called soil pipes. Other drain pipes are called waste lines.

What material expands as temperature decreases?

Water is the only material to expand as it gets colder. This expansion occurs just prior to freezing.


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